Thanks for the input, guys. 100% water changes, by the way, are not harmful to the fish in a 1.5g tank with a filter, right? Aren't 50-75% changes healthier?

That's if the tank is cycled.

For an uncycled 1.5, I would recommend 100% twice a week. Just make sure the new water has the same temperature and pH of the old water.

You can match the temp by adjusting the tap. I know a lot of people are hung up on aging their water for 24 hours, but unlike using water conditioner this will not remove the chloramines and heavy metals from the water. So provided that you have to condition the water whether you age it or not, you might as well just pour it out of the tap and condition after.

Older fishkeeping methods advise against 100% wcs, but the bottom line is that with the technology we have today, there shouldn't be anything stressful about 100% water changes if you are doing it right.